We performed a characterization of the bubbly and slug flow regimes in minichannels in conditions
relevant to microgravity. Two-phase flows were generated on ground by means of a T-junction device
(1 mm i.d.), whose operation is independent to changes in gravity level [1]. Air and water were injected
at several superficial velocities ranging from 0 up to 2 m/s. The generation and detachment of the
minibubbles is provided by the liquid cross-flow (see figure). In nominal conditions small Bond and
Weber numbers are achieved for the air/water mixture flow. Therefore, capillary forces dominate over
buoyancy and inertial forces [2]. Laminar regime can also be assumed. Bubbly, slug, churn and
annular flows were observed (see figure). The characterization consists in the analysis of the bubble
and the unit cell lengths, the bubble velocity and the void fraction in both bubbly and slug flow
regimes.